1. Field of the Invention
The present invention relates to a multi-color small amount painting system, i.e., a painting system in which a variety of colors of paint may be stored in a small unit amount and a desired color of paint may be selectively fed out of them to a painter.
More specifically, the present invention relates to a multi-color small amount painting system in which a large number of different paint colors of paint are stored in the form of paint cartridges, a paint cartridge of the designated paint color is carried to be mounted on a painting robot or an automatic painting device and the paint within the cartridge is fed to its painter.
2. Description of the Related Art
For example, referring to Japanese Utility Model Examined Publication No. Hei 4-46846, Japanese Utility Model Examined Publication No. Hei 4-46847 or the like, in order to enhance the workability of the multi-color painting corresponding to the increased number of the kinds of paint color, there have conventionally been proposed and developed a variety of multi-color small amount paint feeding systems.
Then, in recent years, a painting robot has often been used to paint, for example, an automotive body. Thus, nowadays, there have been proposed some multi-color painting systems for selectively feeding several to ten and several kinds of paint to the painting robot.
For example, Japanese Patent Examined Publication No. He 7-34882 discloses a spray painter in which a plurality of feeding paths P1 to P3 of respective paint colors are provided to be introduced into a working area of a painting robot 14, bottle-shaped reservoirs 22 are connected at fixed positions of the respective feeding paths, the reservoirs are carried by the robot 14 and connected to a spray 20 within the robot by the operation of the robot 14, and the spray painting is carried out.
Also, Japanese Patent Unexamined Application 4-83549 Lt discloses a multi-color painting apparatus in which painting guns 35a to 35n for respective colors and painting intermediate tanks 21a to 21n are arranged to be connectable to or separatable from painting recirculation systems separated in accordance with a painting color in the vicinity of a painting robot 51, one or both of the painting gun and the painting intermediate tank is selectively mounted on the robot 51 by using a mounting robot 41, and paint is discharged by a constant flow rate regulator 61 to thereby make it possible to perform a selective multi-color painting operation.
However, the invention of the above-described spray painter suffers from the following problem. In general, the number of the kinds of paint color is limited to several kinds since the feeding paths of the respective paint colors have to be introduced into the working area of the painting robot. Accordingly, there is a certain limit for enhancing the versatility of the multi-color painting. In addition, in order to introduce the feeding paths of the respective paint colors a into the working area of the painting robot, a very large size equipment is required as a whole. Furthermore, since the exchange of the paint colors is performed by the painting robot itself, it is impossible to simultaneously perform the color exchange operation and the painting operation. In addition, since it is necessary to perform a cleaning operation of the interior of the tank 22 whenever the colors are changed, the working efficiency of the multi-color painting is remarkably degraded.
Also, the invention of the above-described multi-color painting apparatus improves the aspect of the efficiency of the painting operation with the above-described spray painter but still suffers from the following problem. The more versatile the color becomes by increasing the number of the paint color, the wider the working area of the mounting robot expands. This requirement increases the size of the equipment and causes the remarkable broadening of the painting work space, disadvantageously. Also, since the color recirculation system is provided for each painting color, the painting equipment as a whole becomes large in size.
Furthermore, the above-described conventional multi-color painting system is suitable for the case where a relatively large amount paint for one kind of color is to be selectively fed to the painting robot. However, recently, there is a strong demand that an individual consumer of an automotive vehicle may request to paint the automotive body in paint color which is decided by him or her. Thus, the development of the painting technology that may meet such a request is highly appreciated. Under the above-described circumstances, the number of the colors of the paint to be usable for the automotive body painting is increased up to several tens of colors or more. The multi-color painting is further accelerated. On the other hand, corresponding to this trend, the amount of the used paint of the respective paint colors is relatively decreased except for a large amount of paint such as white color paint. Accordingly, there has been a demand for developing a multi-color painting system in which such a large number of colors of paint may be selectively fed to a painting device such as a painting robot in a small unit amount. However, in any of the conventional multi-color painting systems which have been developed, it is impossible to satisfactorily meet this demand.
Also, in the case where the automatic painting operation is performed by using the painting robot or the automatic painting device, in order to perform the painting operation without fail and in a stable manner, in general, it is necessary to automatically control the injection or the spray of paint from the painter in a stable manner.
Accordingly, also in the above-described multi-color painting system, in the same manner, the discharge amount of paint from the painter has to be numerically determined, and in other words, it is necessary to make it possible to feed the paint from the painting cartridge to the painter in a stable manner.